P, a passenger, had bought a rail ticket which he was prevented from using because of industrial action. He sued the union for expenses incurred as a result (statutory protections didn’t apply since the unions were striking without a ballot). Henham J held that D's knew of the existence of contracts between British Rail and passengers who had already purchased tickets at the time the strike was called, and they intended to interfere with the performance of such contracts by inducing British Rail employees to withdraw their labour. The interference with the performance of the contract between P and British Rail was a necessary consequence of the D's actions and therefore they were liable to him for damages.